(Webhook Detection): Created `delete_and_respond` helper function to handle Webhook URLs.

1 files changed, 41 insertions, 2 deletions

diff --git a/bot/cogs/webhook_remover.py b/bot/cogs/webhook_remover.py
index 54222b007..a19f9c196 100644
--- a/bot/cogs/webhook_remover.py
+++ b/bot/cogs/webhook_remover.py
@@ -1,13 +1,24 @@
+import logging
 import re
 
-from discord import Message
+from discord import Colour, Message
 from discord.ext.commands import Cog
 
 from bot.bot import Bot
 from bot.cogs.moderation.modlog import ModLog
+from bot.constants import Channels, Colours, Event, Icons
 
 WEBHOOK_URL_RE = re.compile(r"discordapp\.com/api/webhooks/\d+/\S+/?")
 
+ALERT_MESSAGE_TEMPLATE = (
+    "{user}, looks like you posted Discord Webhook URL to chat. "
+    "I removed this, but we **strongly** suggest to change this now "
+    "to prevent any spam abuse to channel. Please avoid doing this in future. "
+    "If you believe this was mistake, please let us know."
+)
+
+log = logging.getLogger(__name__)
+
 
 class WebhookRemover(Cog):
     """Scan messages to detect Discord webhooks links."""
@@ -21,13 +32,41 @@ class WebhookRemover(Cog):
         return self.bot.get_cog("ModLog")
 
     async def scan_message(self, msg: Message) -> bool:
-        """Scan message content to detect Webhook URLs. Return `bool` about does this have webhook URL."""
+        """Scan message content to detect Webhook URLs. Return `bool` about does this have Discord webhook URL."""
         matches = WEBHOOK_URL_RE.search(msg.content)
         if matches:
             return True
         else:
             return False
 
+    async def delete_and_respond(self, msg: Message, url: str) -> None:
+        """Delete message and show warning when message contains Discord Webhook URL."""
+        # Create URL that will be sent to logs, remove token
+        parts = url.split("/")
+        parts[-1] = "xxx"
+        url = "/".join(parts)
+
+        # Don't log this, due internal delete, not by user. Will make different entry.
+        self.mod_log.ignore(Event.message_delete, msg.id)
+        await msg.delete()
+        await msg.channel.send(ALERT_MESSAGE_TEMPLATE.format(user=msg.author.mention))
+
+        message = (
+            f"{msg.author} ({msg.author.id}) posted Discord Webhook URL "
+            f"to {msg.channel}. Webhook URL was {url}"
+        )
+        log.debug(message)
+
+        # Send entry to moderation alerts.
+        await self.mod_log.send_log_message(
+            icon_url=Icons.token_removed,
+            colour=Colour(Colours.soft_red),
+            title="Discord Webhook URL removed!",
+            text=message,
+            thumbnail=msg.author.avatar_url_as(static_format="png"),
+            channel_id=Channels.mod_alerts
+        )
+
 
 def setup(bot: Bot) -> None:
     """Load `WebhookRemover` cog."""